Magnetic filter



March 7, 1939. J. R. FREI 2,149,754

- MAGNETIC FILTER Filed June 10, 1937 3 Sheets-Sheet 1 INVENTOR.

Era M Miihesg I -iahab TTORNEY.

March 7, 1939. .17 R. FREI 2,149,764

MAGNETIC FILTER Filed June 10, 1957 I '5 Sheets-Sheet 2 March 7, 1939. FRE] 2,149,764

MAGNETIC FILTER Filed June 10, 193'? 3 Sheets-Sheet 3 Patented Mar. 7, 1939 PATENT OFFICE 2.149.764 MAGNETIC FILTER Jakob Rudolf Frei, Sidney, N.

Y., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application June 10, 1937, Serial No. 147,533 10 Claims. (Cl. 210-154) The present invention relates to a magnetic filter and more particularly to a device for separating particles of magnetic material such as iron or steel chips or dust from fluids such as lubricating oil in which such material is suspended.

Various magnetic devices have been proposed from time to time \for separating ferrous material suspended in fluids, but such devices have in general been large and cumbersome in comparison with the corresponding conventional filter units, and have been found ineflicient when the fiow of fluid therethrough was rapid. They also have been in general difficult to clean and maintain at their maximum effectiveness.

It is an object of the present invention to provide a novel magnetic filtering device which is emcient and thorough in its action, while being small and compact in construction.

'Another object is to provide such a device which may be readily disassembled for cleaning.

A further object is to provide such a device which is so arranged that in reassembly of the parts, proper correlation'thereof is assured.

Further objects and advantages will be apparent from the following description taken in connection with the accompanyingdrawings in which:

. Fig. l is a vertical sectional view of a preferred embodiment of the invention taken substantially on the line i--l of Fig. 3.

Fig. 2 is a top end view of the filter unit;

Fig. 3 is a cross section taken substantially on the line 3-3 of Fig. 1;

Fig. 4 is a vertical sectional view of a second embodiment of the invention involving a more compact arrangement of the filter, taken substantially on the line 4-4 of Fig. 6;

Fig. 5 is a section of the filter unit taken substantially on the line 5-5 of Fig. 4;

Fig. 6 is a top end view of the filter unit;

Fig. '7 is a detail in perspective partly broken away of the outer filtering element of the structure illustrated in Fig. 4;

Fig. 8 is a similar view of the inner filtering element;

Fig. 9 is a similar view of the upper mounting collar for the filter unit; and

Fig. 10 is a detail inperspective of the magnet and battle assembly unit.

Referring first to Fig. 1 of the drawings, there is illustrated a casing member I providing a chamber 2 having a port 3 in one end thereof and a second, port 4 in the side thereof. It

will be understood that the ports 3 and 4 are provided with suitable connections to the circulating system for the fluid which is to be purified. Thus, in case the filter unit is utilized for the extraction of ferrous material from the lubricating system of an internal combustion 5 engine, the lubricant is caused to flow through the chamber 2 on its way either to or from the circulating pump of the engine as is customary with ordinary filtering devices.

In the chamber 2 a cylindrical filtering de- 10 vice 5 is mounted comprising a sieve or strainer preferably composed of two layers 6 and I of foraminous material of different degrees of fineness, the coarser mesh material being so placed as to support and reenforce-the flne mesh ma- 15 terial in respect to the pressure of the fluid thereon. Thus if, as illustrated, the-flow of fluid is in the direction of the arrows a and flows out through-the scre' e'n,. the' coarse mesh material 6 is placed-outsidethe fine mesh screen 1. 20

The screens 6 and] are formed of magnetizable material and-a .series of baiile plates 8 of magnetizable material are arranged within the fllter unit 5 at spaced intervals throughout its length. Between the baflles 8, cylindrical per- 25 manent magnets 9 are mounted with like poles in engagement with each baiile as indicated, so that the baffles are magnetized with opposite polarity in sequence.

End mounting collars ii and i2 are arranged 30 to receive the ends of the screens 6 and 1 and are provided with openings i3 and i4 registering with the openings in the magnets 9, and means in the form of a bolt i5 is provided for traversing said openings and clamping all the parts 35 of the filter into a unitary assembly.

Casing i is provided with a shoulder i6 forming a seat for the collar ii of the filter unit adjacent the port 3, and a plug I1 is arranged to be threaded into an opening l8 in the casing 40 and is provided with a seat iii to receive the collar i2 of the filter unit.

Collar ii is provided with a series of openings 2i, and the baiile plates 8 are provided with a plurality of serrations or notches 22 permitting 45 fluid to fiow through the interior of the filter unit 5.

In the operation of the device, when the filter unit is assembled in the chamber 2 as illustrated, the collars ii and i2 are tightly held in 50 the seats i6 and i9 so that the liquid coming through the port 3 is forced to enter the filter unit through the openings 2i and emerges through the screens 6 and 1 so as to leave the chamber 2 by means of the port 4. In passing 55 through the filter unit 5, the fluid is forced to flow by the multitude of edges and corners provided by the magnetized baflie plates, and the magnetic material in the fluid adheres to such edges and also to the wires of the screens 6 and I which are also magnetized by their engagement with the peripheries of the baffle plates.

When it is desired to clean the filter, it is merely necessary to unscrew the plug l1 and draw out the filter unit. Removal of the bolt l5 then permits disassembly of the unit, and since the parts become demagnetized as soon as the magnets 9 are removed, it is a simple matter to wipe the deposited ferrous material therefrom, with the aid of a solvent such as kerosene or gasoline if desired.

In some cases it is desirable to form the magnets and baiiies as a unit which cannot be readily disassembled in the field, in order to prevent the possibility of the magnets being inadvertently reassembled in inverted relation. This may be accomplished, as illustrated, by riveting over the head 20 of the bolt l5, and pressing or swaging on a retaining member such as a washer 30 bearing against the bottom ballie 8 to retain the bailies and magnets assembled, while permitting the removal of the collar 2 and screens 6, I.

In the embodiment of the invention illustrated in Figs. 4 to 10 inclusive, a more compact arrangement of the filter unit is provided by in effect telescoping it upon itself. As illustrated in Fig. 4, a housing 23 is provided forming a chamber 24 having an end port 25 and a side port 26. The filter unit in this case comprises two concentric screens 21 and 28 preferably of composite structure similar to that employed in the first embodiment of the invention described.

The upper end of screen 21 is provided with a reenforcing and sealing ring 29 which is arranged to bear against an upper mounting collar 3|. Collar 3| is provided with an upward extension 32 having a sliding fit in an annular shoulder 33 formed in the interior of the casing 23 at the port 25. The lower end of the screen 21 is provided with a mounting ring 34 which is arranged to seat on a shoulder 35 in a lower mounting collar 36 threaded into the lower end of casing 23.

The upper end of screen 28 is also provided with a reenforcing and sealing ring 31, and a disc or plate 38 is mounted in said ring so as to close the upper end of the screen. The lower end of the screen 28 is provided with a mounting ring 39 which is complementary to the mounting ring 34 of screen 21 and cooperates therewith to close at the bottom the annular space between the two screens. Annular baflie plates 4| of magnetizable material having serrations on their inner and outer edges are mounted in the space between the inner and outer screens, and between the baflie plates groups of permanent magnets 42 are mounted with like poles adjacent each baflle plate. The top and bottom baflle plates 4| are permanently tied together by suitable means such as riveted bars 43. The mounting collar 3| is attached to the upper bafile plate 4| by suitable means such as cap screws 44, and the mounting rings 34 and 39 are attached to the lower baiile plate 4| as by means of cap screws 45 and 46 respectively, mating tongues 41 and 48 and depressions 49 and 5| being provided on the rings 34 and 39 respectively for the reception of the cap screws 45, 46.

Suitable packing material 52 is preferably provided between the shoulder 33 of the casing 23 and the mounting collar 3|, which packing is placed under compression by the filter unit when the lower collar 36 is tightened up.

In the operation of this embodiment of the invention, assuming that the fluid enters at the port 28 and emerges at the port 25, the fluid enters the filter unit from the outside through the screen 21 and from the inside through the bottom and the screen 28, after which it flows up past the annular baflle plates 4| and emerges from the top of the unit. In flowing through the meshes of the screens and past the multitudinous edges and corners of the baflie plates, the ferrous material in the fluid is extracted by the magnetized parts and the fluid thereby purified.

When the filter unit is to be cleaned, it is merely necessary to remove the lower mounting collar 86, whereupon the filter assembly may be withdrawn. Removal of the cap screws 45 and 46 permits the disassembly of screens 21 and 28 respectively, whereupon the baffle plates may be readily wiped clean and the screens washed and wiped in the usual manner. It is unnecessary to further disassemble the filter unit for cleaning purposes and since the parts can only be assembled in the proper manner, the proper relationship of the magnets and magnetic elements in the filter when reassembled is ensured.

Although but two embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and various changes may be made in the design and arrangements of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

i. In a magnetic filter for fluids, a chamber having a fiuid port, a cylindrical filter body having a fluid-tight fit in said port and having an axial fluid passage therethrough and a peripheral envelope of foraminous magnetic material, a plurality of magnets arranged longitudinally in the filter body with like poles adjacent, and a plurality of baflies of magnetic material with serrated edges interposed between like poles of said magnets.

2. In a magnetic filter for fluids, a generally cylindrical chamber having an axial fluid port, a cylindrical filter body having a fluid-tight fit in said port and having an axial fluid passage therethrough and a peripheral envelope of foraminous magnetic material, a plurality of permanent magnets arranged longitudinally in the filter body with like poles adjacent, and a plurality of baflie plates of magnetic material interposed between like poles of said magnets with serrated peripheral edges adjacent the envelope.

3. In a magnetic filter for fluids, a generally cylindrical chamber having an axial fiuid port, a cylindrical filter body having a fluid-tight fit in said port and having an axial fluid passage therethrough and a peripheral envelope of foraminous magnetic material, a plurality of groups of permanent magnets coaxially arranged with like poles adjacent, and a plurality of magnetic baflle plates with serrated edges interposed between the groups of magnets and extending across the filter body.

4. In a magnetic filter, a cylindrical casing havinga port at one end, and a cylindrical filter unit fitting at one end in said port comprising a pair of concentrically arranged filters of magnetic material, a plurality of groups of permanent magnets arranged between the inner and outer filters, with annular magnetic bafiles having serrated edges interposed between the like poles thereof, and

means for directing the flow oi fluid into the spaces between the filters.

5. In a magnetic filter, a cylindrical magnetizable screen, means for directing the flow of a fluid through the screen, a series of circular magnete izable baflle plates in the screen having serrated edges adjacent the screen, and a plurality of permanent bar magnets spacing the baflles with like poles engaging each baflle.

6. In a magnetic filter, a cylindrical magnetizable screen, means for directing the flow'oi a fluid through the screen, a series of circular magnetizable baflle plates in the screen having serrated edges adjacent the screen, a plurality of perma-- nent bar magnets spacing the bailles with like poles engaging each baflie, and means traversing the baflies for unifying the assembly of magnets and baflles.

'7. In a magnetic filter, a pair of concentric cylindrical magnetizable screens, meansfor directing the flow of a fluid through said'screens and the annular chamber therebetween, a. plurality of magnetizable annular baliies located at spaced intervals within said chamber, and permanent magnets arranged axially within said chamber between the baflles, with like poles engaging said baiiies.

8. In a magnetic filter, a pair of concentric cylindrical magnetizable screens, means for directing the flow of a fluid through said screens and the annular chamber therebetween, a plurality of magnetizable annular bames with serrated edges located at spaced intervals within said 'outside the outer screen and inside the inner screen, a partition closing the end of the space between the screens opposite the end port, magnetizable baflles in said space, and permanent magnets spacing said baflies with like poles engaging each baille.

10. In a magnetic filtering device for fluids, a cylindrical chamber having an end port and a side port, a pair of concentric cylindrical magnetizable screens in the chamber, means for connecting the end port to the annular space between the screens,

means for connecting the side port to the spaces outside the outer screen and inside the inner screen, a partition closing the end of the space between the screens opposite the end port, annu-- lar magnetizable baflies in said space having serrated edges adjacent said screen, permanent bar magnets spacing saidbaflles with like poles engaging each bailie, and means traversing the baiiles for unifying the assembly of baflies and 30 magnets.

JAKOB RUDOLF FREE. 

